X t telephone receiver



Feb. 21, 1928.

E mu m D R m w .P.v E

Original Filed Dec. 5. 1924 I construction and to improve the efliciency by Reiuued Feb. 21, 1928.

" Re. 1636i OFFICE.

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'rnmrronn Brennan Original Io. 1,804,251, dated October 86, 1886, Serial No. 754,183, Med December 5, 1824. Application 101' relnue fled October 7, 1927. Serial -1I'o. 224,735.

The present invention apfpertains to telephone receivers and is particularly an imv provement over my former Patents No. 957,403, issued May 10, '1910, and No. 1,153,593 issued Sept. 14,1915.

The objects are to further simplify the providing a magnet of greater capacity.

The invention is illustrated in the accompanying drawing wherein Fig. 1 is an elevation of-the instrument having the bottom of the shell cutaway. Fi .2 is an elevation of the instrument at rig t an les to that shown in Fig. 1 and showing earpiece in section along the me of Fig.

. 1, and Fig. 3 is a metrical section along the line CD of Fig. 1, showing the arrangement of the various workin parts. I

. In the figures of t 1e drawin numeral 1 designates the shell or casing w ich has the rim of the annular base'plate 2 seated against its edge. To this base plate the horse shoe magnet 3 is secured by means of solder, screws, or other means not shown.

The opposite parallel surfaces of the poles of the magnet 3 are provided with U-shaped polepieces land 5 which are secured to the magnet by means of screws or otherwise.

a The limbs of these (polepieces are partly cut 30 away and arrange so that the remaining portions overlap each other as shown in Fig. (1521 leaving a narrow space between their etween the limbs of the pole ieces 4 and 5 the spool 6 is located and hel firmly and accuratel in proper position, being surrounded y the said (p0 epieces and the projecting edges 7, 7 an 8, 8 which are formed upon them. 4.

Within the spool 6 the armature 9 is held in (position by flexible fulcrum wires 10, 10

its ends project on either side midway between the edges of the limbs of the, polepieces-4 and 5.

At one end the armature 9 is connected by a bolt 11, washer 12, and nut 13 to the cen-,

ter of the diaphragm 14 which is seated upon the rim of'the base plate2 and clamped in positionby the earpiece 15. At the other end the armature 9 is acted upon by( a spring 16 one end of which fits into a $00 et in the armature 9 and the other end fits into a socket in the end, of the adjusting screw 17. By means of this adjusting screw 17 which t e shell and diaphragm.

is tapped into the insert 18 set in the polepiece 5, and the nut 13 the armature 9 can be set in-the proper position between the pole ieces and the tension of the diaphragm can adjusted.

Upon the base plate 2 and within the magnet 3 a block of insulatin material 19 is Socured by a screw 20, an screws 21, 21 are tapped 1nto this block 19. The terminals of the winding uponthe spool 6 are. soldered to washers 22, 22 and the cord ti s 23, 23 are heldin contact .with these was ers by the screws 21,21. I 1

The improved; combination of magnet, polepieces, coil and armature, as herein disclosed, are incor rated in a telephone receiver and applie to a lain diaphragm, but

it is obvious that simi ar combinations can be applied to other forms of acoustic elements, such as a cone diaphragm or phonograph stylus and incorporated in other acoustic instruments, such as loud speakers, inductive transmitters, inductive phonograph reproducers, or electrical phonograph recorders; 4 'I claim:

1. A telephone receiver comprising a spool containing the actuating winding, an armacontaining the actuating winding, an armature fulcrumed within said spool, U-shaped upon said armature, projecting edges upon aid polepiecesto hold said'spool in proper position, a magnet contactlng with 'said polepieces, a diaphragm, and means'to transmit the movements of said armature to said 3. A telephone receiver comprising a horse-shoe magnet, U-shaped, polepieces attached to the poles of said magnet with the limbs of one polepiece overlapping the limbs of the other, a spool containing the actuating winding inclosed by said polepieces, projecting edges formed upon said polepieces to hold said spool in proper position, an armature fulcrumed within said spool and acted polepieces inclosing'j-said spool and acting I armature.

ing-edges formed upon said polepieces to' hold said spool in proper position, an armature fulcrumed within said spool and acted upon by the overlapping limbs of said pole- -p1eces,'a diaphragm, and means to transmit the movements of said armature to said diaphragm.

5. An acoustic instrument comprising a U-. shaped magnet, U-shaped polepieces attac ed to the oles of said magnet,-a'n actuating coil inc osed bysaid polepieces, projectin ed es formed upon said polepieces, to hol said coil in proper position, an arma-' ture passing throughsaid coil and acted upon y said polepieces, an acoustic element, and'means operatively connectlng said armature with said acoustic element,

6. An acoustic instrument comprising a U-sha ed magnet, U-sha ed polepieces atjectin tache to the poles of sai ma ating coil inclosed b said po e1pieces, projecting ed es forme upon sai polepieces to hold sai coil in proper position, an armature passing through said coiland acted upon y said polepieces, a fulcrum for said armature, an acoustic element, and means operatively' connecting said armature with said acoustic element.

7. An acoustic instrument comprising a U-sha d magnet, U-sha ed polepieces attache to the oles of said ma net, an actuating coil incibsed b said po epieces, proedges forme to ho (1 said coil in pro e11. position, an armature passing throng said coil and acted upon by said olepieces, a fulcrum 'for'said armature wit in said coil, an acoustic element, and means operatively connectlng said armature with sand acoustic element.

8. Anacoustic instrument comprising a U-sha ed magnet, 'U-shaped polepieces attache to the poles of said magnet, an actuating coil, a spool containing said actuating coil and inclosed by said pole ieces, projectin edges formed upon sai polepieces to ho d said spool in proper osition, an armature plassin through sai spool and acted upon y sai polepieces, an acoustic element, and means-operatively connecting said armature with said acoustic element.

9. An acoustic instrument comprising a U- shaped magnet, U-shaped polepieces attached to the poles of said magnet with the limbs of one polepiece overlapping the limbs of the other, an actuating c011 inclosed by said polepieces, projecting edges formed upon et, an actuupon said polepieces the limbs of saidpolepieces to hold said coil in proper position, an armature passing through said coil and acted upon by said polepieces, an acoustic element, andmeans operatively connecting said armature to said acoustic element.

10. An acoustic instrument comprising a U-sha ed magnet, U-shaped polepieces attached to the poles of said magnet with the limbs of one polepiece overlapping the limbs of the other, an actuating coil, a spool containing said actuating coil inclosed by said polepieces, projecting edges formed upon the limbs of said polepieces to hold said spool in proper position, an armature assing' through said spool and acted upon y said polepieces, a fulcrum for said armature, an

acoustic element, and means operatively piece attached to each of sai inner pole faces,

and having two limbs extending toward the opposite pole .face of said magnet, the limbs of one of said polepieces overlapping the limbs of the other polepiece, an actuatin coil, a spool containing said coil and inclose by said polepieces, projecting edges on the limbs of said polepieces to hold said spool in osition, an armature passing through sai spool and between the overlapping limbs of said polepieces, an acoustic element and means operatively connecting said armature with said acoustic element.

13. "An actuatin coil, two pole ieces inclosing said coil, having two lim s of one polepiece overlapping two limbs of the other polepiece, projecting edges on said polepiece limbs to hold said coil in position, an armature passing through said coil and between the overlapping limbs of said polepieces, a magnet contacting with said polepieces, an acoustic element and means 0 ratlvely connecting said armature with said acoustic element. p 14. An actuating coil, a spool containin' said coil, two polepieces inclosing said spoo having two limbs of one polepiece o'verl apping two limbs of the other polepiece, proectmg edges on said polepiece limbs to hold said spool in position, an armature passing through said spool and between the overlapping limbs of said pole ieces, a magnet contracting with said po epieces, an acoustic '10 polep'ieces and said coil.

-16. An acoustic device comprising U--' element and means 0 rativeiyoonnecting said armature with sai acoustic element.

15. An aoustic device comprising an ac tuated boil, bifurcated polepleees between positioning means extendi from a leg of a polepiece toward the o ifier leg thereof, a magnet contacting said polepieces,and anarmature disposed to be acted upon by said the legs of which said coil is disposed, coilshaped'polepieces, a spool disposed between i the legs of said polepieoes, an actuatingyvinding on said spool, means extending] from a. leg of a polepiece'toward the other 18f leg thereof and disposed in contact with said spool, a magnet disposed to magnetize said polepieces,;. and an armature. mounted tohe acted upon by said polep ieces and said NATHANIEL BALDWI'Ni- 

